Washing machine



Jan. 21, 1964 H. w. GESCHKA ETAL 3,118,296

WASHING MACHINE Original Filed Oct. 12, 1959 INVENTOHS HUGO W. GESCHKAJOSEF L. GILLESSE/V United States Patent 6 8 Claims. or. 68-16) Washingprocesses carried out in automatic washing machines are known in whichwater is continuously supplied to the washing liquid in the washingcontainer of the machine while at the same time an equal quantity ofliquid is removed from the container through an overflow. Such processesare disclosed in commonly assigned copending application Ser. Nos.764,419, new Patent No. 3,071,432, and 834,292 and application Ser. No.845,681 and now abandoned of which present application is a division. Inthis manner the dirt detached from the material being washed iscontinuously removed from the container with the upper layer of washingliquid which is continuously being run off. In order to keep theconsumption of washing agent and heat as low as possible, the quantityof water which is continuously added and removed should not be toogreat. 0.08 to 0.15 litre per minute and per kilogram of dry material tobe washed is considered to be a suitable quantity for this purpose.Since in this process a considerable proportion of the dirt is removedrelatively early from the container after detachment from the material,the number of separate washing stages can be reduced without impairingthe washing effect, and an economical method of washing can thereby beachieved. The so-called degree of whiteness, however, which is anindication of well cared for washing, is not as great as would beexpected.

In order to overcome this diiliculty, according to the inventiondescribed in application No. 7 64,419, the washing operation is carriedout in two stages, during the first of which a continuous supply anddischarge of water takes place to and from the washing container and thewashing liquid in the container is heated and during the second of whichthe supply and discharge of water is discontinued but heating ismaintained until the end of the washing process. This results not onlyin a considerable saving in heat and washing agent but also gives thedesired greater degree of whiteness.

By far the greatest proportion of the dirt which becomes detached fromthe material being washed enters the washing liquid at an early stage,when the temperature is still fairly low, and is removed from thecontainer with the water flowing ofi. In the second stage, onlycomparatively minor residues of dirt are left in the washing. These arethen easily removed by the static washing liquid, which heats up morerapidly, so that the desired degree of whiteness is achieved.

It is here that the principle of the present invention comes into play.It is based on the following consideration: it one operates with a smallliquid ratio, i.e. with a small quantity of washing liquid per kilogramof dry material being washed, the heating of the washing liquid in thesecond stage, in which the water supply and discharge is discontinued,to the desired temperature, e.g. 90 C., can be carried out more rapidlyand with less consumption of heat energy. A small liquid ratio istherefore desirable, this ratio varying with the nature of the materialbeing washed and the extent to which it is soiled. On the other hand, ifa small quantity of liquid is used, the upper layers of the water willcontain a correspondingly greater concentration of dirt. This can becountered, however, by increasing the amount of water "ice continuouslysupplied and discharged in the first washing stage.

Accordingly, as a further development of the process described inApplication No. 764,419 it is now proposed to use an adjustable quantityof liquid in the container and to adapt the rate of continuous supplyand discharge of water to the quantity of liquid in the container ineach case.

It is, therefore, the principal object of the present invention toprovide a novel washing machine in which this process can be carried outefficiently and more or less automatically.

According to the present invention, in the process described above withreference to application No. 764,419 the volume of water held by thecontainer is adjustable but the total volume of water supplied to anddischarged from the container in the first stage and remaining in thecontainer in the second stage is between 4.4 and 5.5 litres per kilogramof dry material washed. Preferably a total of 5.0 litres of water areused per kilogram of dry material to be washed. Preferably, etween 2.7and 3.8 litres per kilogram of dry material of washing is used forfilling the container and a constant amount of 0.14 to 0.05 litre ofwater per kilogram of dry material per minute is supplied and dischargedin the first stage. It has been found that really satisfactory washingresults can be obtained only if the quantity of water used for fillingthe container is kept within the limits given above when using theprocess of the invention. The figures show that it is possible to obtaina satisfactory result with a smaller quantity than would hitherto havebeen considered possible provided the rate of constant supply anddischarge of water is adjusted accordingly.

The invention is described below with reference to a number of examples:

If the container contains 3 litres of water per kilogram of dry materialto be washed and the total quantity of water used in the first phase,which lasts for example 20 minutes, is 5 litres, then the quantity offresh water which must be supplied per minute and per kilogram of drymaterial is 2:20:01 litres. With the same total quantity of water andthe same duration of the first washing stage but with 4 kilograms ofwater per kilogram of dry material, only 0.05 litre of fresh water areadded and removed per minute and per kilogram of dry material. If thetotal quantity of water to be used in the first stage is 4.6 litres perkilogram of dry material, and if the water level in the container isadjusted so that the container contains 3.5 litres per kilogram of drymaterial, then, if the first stage is to last 15 minutes, the quantityof water supplied and discharged per minute is 1.1:15=0.073 litres perkilogram of dry material.

As already mentioned above, a saving in heat can be obtained by reducingthe level to which the container is filled in the second stage. As thetotal quantity of water supplied to and partially removed again from thecontainer during the first stage is constant, and the heat removed inthis stage is practically negligible, one can assume the quantity ofheat used to be practically the same, regardless of the quantity ofwater required in each case for filling the container. A considerabledifference regarding the heat energy to be consumed occurs in the secondstage, however, which is carried out with the water supply and dischargecut off. In this stage, the consumption of heat is approximatelyproportional to the volume in the container assuming the finaltemperature is always the same, for example C. If, therefore, the supplyof electricity to a washing machine adjusted, for example, to a liquidratio of 4:1 is 0.7 kw. per kilogram of dry material, then if thewashing machine is readjusted to a *same time, the heater is switchedon.

, 17 and 18 are provided in the container 13.

3 liquid ratio of 3:1, the supply would drop to 0.54 kw. per kilogram ofdry material.

An automatic washing machine suitable for carrying out this process has,like the machine described in application No. 764,419 a water inlet andan outlet leading to the container and controlled by a regulating valve.The water outlet is adjustable in height and the regulating valve in thewater inlet is controlled in dependence on the height adjustment of theoverflow.

Further features of the invention will be described by way of examplewith reference to the accompanying drawings, in which:

FIGURE 1 shows a graph to explain the process; and

FIGURE 2 is a diagrammatic illustration of a washing machine accordingto the invention.

In the graph shown in FIGURE 1, the time t is shown as the abscissa andthe temperature T of the washing liquid is shown as the ordinate. Whenthe washing container has been filled with a quantity of watercorresponding to the adjusted level of the outlet the first washingstage begins at the point P A certain quantity of Water is suppliedcontinuously. An equal quantity is removed through the outlet oroverflow of the machine. At the The temperature of the water risessteadily but not quite linearly up to the point P This temperature riseduring the time t is indicated by the part 1 of the graph. Since, thetotal quantity of water used during this time is constant, the change inthe gradient of the part 1 of the graph is so slight, when the limitsgiven above are observed, that it may be neglected. At the point in timeP when the constant supply and discharge of water is stopped, the firstwashing stage is completed. In this stage, which may be termed thepreliminary wash, the coarse dirt is removed through the overflow alongwith the constantly discharged water. In the second washing stage, whichnow begins, the temperature of water rises rapidly, and the smaller thequantity of water in the container, the more rapidly will thetemperature rise. This course of temperature variation is shown inFIGURE 1 by the lines 3, 4, 5. The line 3 corresponds to a quantity of 3litres in the container, line 4 corresponds to 3.7 litres and line 5corresponds to 4.4 litres of water all per kilogram of dry material. Theconsumption of heat energy in the second washing stage is approximatelyproportional to the heating period, i.e. to the times t t 23-13 and t -tin the examples shown.

In the machine shown in FIGURE 2, a setting lever 7 which controls aregulating valve 3a fitted into an inlet pipe 8 leading to the container13, is actuated by a Bowden cable 6. An overflow device is attached tothe Bowden cable 6 by a connecting member 9 so that the overflow 19 isadjustable in height. The arrangement of the Bowden cable is such thatas the height of the overflow 10 increases, the through-flowcross-section of the valve 8a for the water inlet decreases andconversely. To actuate the Bowden cable 5, in order to adjust the levelto which the container 13 is filled and to adjust the quantity of waterconstantly flowing in through the valve 8a, a manually operated switch11 is provided at the front of the washing machine. This switch iscombined with a suitable scale 12 with the inscription low, medium andhigh, and with it the desired liquid level of the machine and thecorresponding quantity of fresh water can be adjusted.

In the embodiment shown, three heating elements 16, These can beswitched on separately or in combination through a switch 14, 15. If theheating time or alternatively only the duration of the second washingstage is to be kept constant. The appropriate number of heating elementscan be automatically switched on or off through the switch 14, 15connected to the Bowden cable 6. In the present case, when the overflow10 is set at its highest, all three heating elements 16, 17, 18 areswitched on.

4 When the overflow is set at medium height, the elements 16, 17 areswitched on, and when the overflow is at its lowest, only the heatingelement 16 is switched on. It is, however, also possible to control theheating elements 16, 17, 18 by a thermostat.

We claim:

1. In a washing machine, in combination, a housing forming a chamber fora washing liquid, agitating means in said chamber for repeatedlydisplacing soiled articles in said chamber through the liquid containedtherein, inlet means terminating in said chamber for supplying saidwashing liquid thereto, adjustable-level outlet means in said housingforming an overflow for excess liquid and conducting said excess liquidout of said chamber, said inlet means including an adjustable valve forselectively regulating the rate of flow of said liquid into saidchamber, coupling means interconnecting said outlet means and saidvalve, and manually operable setting means connected with said couplingmeans for positioning said outlet means to maintain a predeterminedsubstantially constant volume of said liquid in said chamber whileconcurrently positioning said valve so as to maintain substantiallyconstant the total quantity of water employed to treat said articles atsubstantially all positions of said outlet means.

2. In a washing machine, in combination, a housing forming a chamber fora washing liquid, agitating means in said chamber for repeatedlydisplacing soiled articles in said chamber through the liquid containedtherein, inlet means terminating in said chamber for supplying saidwashing liquid thereto, adjustable-level outlet means in said housingforming an overflow for excess liquid and conducting said excess liquidout of said chamber, said inlet means including an adjustable valve forselectively regulating the rate of flow of said liquid into saidchamber, coupling means interconnecting said outlet means and saidvalve, manually operable setting means connected with said couplingmeans for positioning said outlet means to maintain a predeterminedsubstantially constant volume of said liquid in said chamber whileconcurrently positioning said valve so as to maintain substantiallyconstant the total quantity of water employed to treat said articles atsubstantially all positions of said outlet means, and means in saidchamber for heating the liquid contained therein.

3. The combination according to claim 2 wherein said heating meanscomprises circuit means operatively connected with said outlet means forincreasing the thermal output of said heating means upon adjustment ofsaid outlet means to increase said predetermined volume of liquid insaid chamber.

4. The combination according to claim 3 wherein said heating meansincludes a plurality of heating elements, said circuit means includingswitch means for individually and combinatively energizing saidelements.

5. The combination according to claim 4 wherein said coupling meanscomprises a flexible cable interconnecting said outlet means, settingmeans, valve and switch means.

6. The combination according to claim 2, further comprising indicatormeans co-operating with said setting means for providing a visualindication of the position of said outlet means.

7. In a washing machine, in combination, a housing forming a chamber fora washing liquid, agitating means; in said chamber for displacing soiledarticles therein rela-- tive to said liquid, variable-flow inlet meansterminatingin said chamber for supplying said washing liquid thereto,adjustable-level outlet means in said housing forming an overflow forexcess liquid and defining the quantity of residual liquid within saidchamber, heating means including a plurality of heating elementsenergizable for heating the washing liquid therein at varying rates, andcommon control means for said heating means, said inlet means and saidoutlet means including a manually operable switch element forselectively regulating the rate of flow of said liquid into said chamberin dependence upon the level of said outlet means and controlling thethermal output of said elements in dependence upon the volume of liquidretained in said chamber.

8. In a Washing machine, in combination, a housing forming a chamber fora Washing liquid, agitating means in said chamber for displacing soiledarticles therein relative to said liquid, variable-flow inlet meansterminating in said chamber for supplying said Washing liquid thereto,adjustable-level outlet means in said housing forming an overflow forexcess liquid and defining the quantity of residual liquid within saidchamber, heating means including a plurality of heating elementsenergizable for heating the washing liquid therein at varying rates,common control means for said heating means, said inlet means and saidoutlet means including a manually operable switch element forselectively regulating the rate of flow of said liquid into said chamberin dependence upon the level of said outlet means and controlling thethermal output of said elements in dependence upon the volume of liquidretained in said chamber, and a visual adjustment scale mounted uponsaid machine and connected with said control means for indicating thesetting thereof.

References Cited in the file of this patent UNITED STATES PATENTS1,931,410 Hullings Oct. 17, 1933 FOREIGN PATENTS 163,257 Australia June8, 1955 214,993 Australia June 9, 1955

1. IN A WASHING MACHINE, IN COMBINATION, A HOUSING FORMING A CHAMBER FORA WASHING LIQUID, AGITATING MEANS IN SAID CHAMBER FOR REPEATEDLYDISPLACING SOILED ARTICLES IN SAID CHAMBER THROUGH THE LIQUID CONTAINEDTHEREIN, INLET MEANS TERMINATING IN SAID CHAMBER FOR SUPPLYING SAIDWASHING LIQUID THERETO, ADJUSTABLE-LEVEL OUTLET MEANS IN SAID HOUSINGFORMING AN OVERFLOW FOR EXCESS LIQUID AND CONDUCTING SAID EXCESS LIQUIDOUT OF SAID CHAMBER, SAID INLET MEANS INCLUDING AN ADJUSTABLE VALVE FORSELECTIVELY REGULATING THE RATE OF FLOW OF SAID LIQUID INTO SAIDCHAMBER, COUPLING MEANS INTERCONNECTING SAID OUTLET MEANS AND SAIDVALVE, AND MANUALLY OPERABLE SETTING MEANS CONNECTED WITH SAID COUPLINGMEANS FOR POSITIONING SAID OUTLET MEANS TO MAINTAIN A PREDETERMINEDSUBSTANTIALLY CONSTANT VOLUME OF SAID LIQUID IN SAID CHAMBER WHILECONCURRENTLY POSITIONING SAID VALVE SO AS TO MAINTAIN SUBSTANTIALLYCONSTANT THE TOTAL QUANTITY OF WATER EMPLOYED TO TREAT SAID ARTICLES ATSUBSTANTIALLY ALL POSITIONS OF SAID OUTLET MEANS.